Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Better research efforts, educational programs and diagnostic tools are needed to combat infectious disease threats against women, Centers for Disease Control and Prevention officials said at the first International Conference on Women and Infectious Diseases in Atlanta.

Women in much of the world are more vulnerable than men to diseases including HIV and AIDS, tuberculosis and malaria, Dr. Julie Gerberding, CDC director, said at the opening of the two-day conference that concluded Saturday.

For example, 55 percent of adult HIV and AIDS infections in sub-Saharan Africa are in women, more than double the rate of female infections in Europe and in the United States. Malaria affects more pregnant women and children under age 5 than other groups.

“We have a lot of theories but really we don’t know why women and girls are disproportionately affected by these diseases,” Gerberding said.

Lack of accessSome health experts say a lack of access to health education and services combined with other social and economic factors prevent women, particularly in impoverished areas, from avoiding infectious diseases.

Health officials are pushing countries to start collecting separate health data on women instead of combined data on men and women.

“We need to do much more,” said Dr. Mirta Roses Periago, director of the Pan American Health Organization on Saturday. “The communities and groups affected still don’t know they are still so far behind.”

Health officials also are being trained to help broaden female access to health information and to empower women in health matters. The United States and other countries are providing more funding to improve women’s health around the world.

“There are hopeful signs that finally the world is beginning to embrace the issue,” Gerberding said. “I’m very optimistic a collective effort will begin to make a difference.”